Table 1 Demographic and clinical features of patients with primary late-onset dystonia according to the site of dystonia onset

	Presentation of dystonia
	Blepharospasm (n = 124)	Cervical dystonia (n = 73)	Focal hand dystonia (n = 26)
Age, years (SD)	70.7 (8.9)^†	60 (13)	55.2 (11.6)
Sex, male/female	30/94	24/49	14/12
Age of onset, years (SD)	55.9 (10.7)^‡	41.7 (13.9)	39.1 (12.6)
Period of follow-up, years (SD)	14.9 (4.9)	16.3 (5.0)	14.8 (4.5)
No of patients (%) who	58 (47%)*	17 (23%)	10 (38%)
experienced spread
Spread to only one body site
No of patients (%)	46 (37)	13 (18)	6 (23)
Age of spread, years (SD)	59.9 (10.6)^§	50.6 (11.3)	52.4 (11.1)
Time to spread, years (SD)	4.5 (5.6)^¶	9.3 (8.5)	14.8 (11.6)
Spread to a second body site
No of patients (%)	12 (10)	4 (5)	4 (15)
Age of spread, years (SD)	65.3 (8.5)	48 (4.0)	56.2 (6.6)
Time from 1^st to 2^nd spread, years (SD)	6.3 (4.5)	8 (2.0)	2.7 (3.0)

Chi square (2 × 3): *p<0.001.
One-way ANOVA: ^†F = 36, p<0.001; Newman–Keuls post-hoc test: blepharospasm different from other groups, p<0.05. ^‡F = 13.8, p<0.001; Newman–Keuls post-hoc test: blepharospasm different from other groups, p<0.05. ^§F = 6.12, p = 0.004; Newman–Keuls post-hoc test: blepharospasm different from other groups, p<0.05. ^¶F = 4.79, p = 0.02; Newman–Keuls post-hoc test: blepharospasm different from other groups, p<0.05.